1970] 
Holldobler — Steatoda 
205 
Fig. 3. Activity of Pogonomyrmex badius at the nest entrance on April 
11, 1970, near Tampa, Florida. Abscissa: average number of ants passing 
through nest entrance during 5 one minute observation periods. Ordinate: 
time of day. 
late afternoon activity. On one occasion a nest was observed soon 
after the web was erected. The first few ants to come out of the 
nest were captured in the silk. They struggled and probably dis- 
charged the mandibular gland alarm secretion (Wilson, 1958) as 
they elicited help from nestmates. However even giant soldiers 
were unsuccessful in their attempts to remove the cobweb and 
